Abstract:

Currently, a special yeast strain for industrial fermentation of sea-buckthorn wine has highly required and it is necessary to screen a fine yeast strain suitable for the fermentation of sea-buckthorn wine. A yeast Y23 was identified by ITS1- 5.8S-ITS2 rDNA sequence analysis and phylogenetic dendrogram construction. Results showed that the complete sequence of 5.8S-ITS rDNA (GenBank Accession: FJ793809) was 874 bp. The yeast Y23 had the nearest heredity with Saccharomyces cerevisiae CBS423T (AM262829), and the homology of their gene sequences were up to 100% so that the selected yeast Y23 was identified as Saccharomyces cerevisiae belonging to the family of Saccharomyces. The yeast Y23 was used as experimental strain to evaluate the effects of initial sugar degree, fermentation temperature and inoculum amount on the quality of sea-buckthorn wine by response surface methodology (RSM). A regression equation with high reliability was obtained and the above technological parameters were optimized using this equation model. Inoculum amount revealed a significant effect on the quality of seabuckthorn wine (P＜0.01). The optimal values of technological parameters for improved quality of sea-buckthorn wine were as follows: original sugar degree 19.9%, fermentation temperature 25.4 ℃ and inoculum amount 10.3%.

Key words: sea-buckthorn wine, yeast, ITS1-5.8S-ITS2 rDNA, identification, application